Growing Green: The Future of Algal Biofuels

Caliginous clouds of smoke and smog emanating from overworked factories illustrate a common depiction of the adverse effects of fossil fuel dependence. This mental image is well-deserved; this dependence has grown in recent years due to a rapidly expanding population and industry, contributing to climate change and pollution. With an increasing dependence on fossil fuels and growing concern for environmental welfare, the government has undertaken efforts in the past several decades to search for a more sustainable method of producing biofuel, emphasizing the need for non-food biofuel crops. In their search for an environmentally friendly and organic fuel constituent, scientists, researchers, and environmentalists have suggested a new ingredient in the production of biofuel: marine microalgae.

Algae, which falls at the bottom of the aquatic food chain, actually has the potential to tackle some big problems, including global warming, climate change, and food insecurity. Microalgae, with its high growth rates, low land and freshwater inputs, and energy-rich oil content, is being proposed as an ingredient in the production of biofuel. Scientists are heralding algae fuel as a more sustainable approach to biofuel manufacturing, making waves in a previously static market.

Algae, which falls at the bottom of the aquatic food chain, actually has the potential to tackle some big problems, including global warming, climate change, and food insecurity.

Although development of biofuel began in the nineteenth century with corn-based fuel, the industry remained relatively inactive until the 1970s oil supply crisis, during which petroleum-based fuel became more expensive, subsequently prompting environmental activists to express their concerns involving leaded gasoline. The government responded with federal and state subsidies for ethanol, but only enacted the first Renewable Fuel Standard (RFS) in 2005, mandating that a certain volume of renewable fuel, varying based on the type of biofuel produced, to replace/reduce a quantity of petroleum-based fuel. However, these federal ethanol mandates, which encourage the production of ethanol made from corn, have indirectly led to a worldwide food price crisis, the ripple effects of which, consisting of decreased U.S. corn exports, a strained global corn supply, and increases in prices of corn and corn substitutes, are still felt today.

After harvesting the algae, scientists remove most of the water and are then able to extract its lipids, energy-rich oils and fats, which are then processed into biofuel. With the lipids harvested from the microalgae, the remaining defatted but protein-rich biomass can still be put to use as an additive to feeds for farm animals or for fish in aquacultures. Charles Greene, principal investigator at the Cornell Algal Biofuel Consortium, says that he views this repurposing of algae “waste” as “providing food security for the world.” Algae will not only help supply the world’s demand for liquid fuel, but also its demand for food through its secondary role as a constituent of farm feed. Algae provides an “integrated solution to so many of society’s greatest challenges,” from the demand for biofuel to sustainability in the food market to efforts towards waste minimization.

But while the prospect of algae biofuel as an alternative fuel source seems promising, several major companies, such as Shell and ExxonMobil, are abandoning their investments in the fuel. Algal biofuel producers struggle to compete with plummeting oil prices, and despite not needing arable land or freshwater, the costs of maintaining a large-scale algae farm can prove too high. Algae farms must maintain the costs of power plants, factories, and water treatment plants. In addition, building the ponds in which to grow algae is an expensive expenditure; the open raceway ponds needed to effectively grow algae in a large-scale operation are costly to construct and to maintain. Producers also risk the contamination of these ponds by predators who feed on algae. In addition, algae cannot trap carbon dioxide quickly enough to support an industrial operation; instead, carbon dioxide must be supplemented for large-scale algae production. Providing enough light and nutrients for the algae to grow is costly upkeep. Furthermore, farming algae is a new frontier; scientists and producers, such as members of San Francisco biotech firm Solazyme, are still experimenting with sustainable methods in growing, harvesting, and processing algae on a larger scale.

The failing algal biofuel industry faces numerous barriers, and while many companies have deserted this environmentally friendly fuel, scientists believe that algae fuel production can still be salvaged through a practice known as “biorefinery.” In the process of biorefinery, biomass is processed into a spectrum of marketable products, rather than just a single one. Algae has the potential to produce a diverse range of products; as excellent sources of vitamins, minerals, and proteins, algae can be processed into antioxidant capsules, health drinks, and other prebiotic food products; algae can also be refined into bioplastic, an environmentally friendly alternative to regular plastic. Diversifying lines of algae products may be able to resurrect the algae fuel industry. Many of these products are high-value chemicals, which sell for a much higher price than biofuels. In combination with biofuel production, these algae products could subsidize the price of the fuel and offset the costs of algae cultivation, making the algae fuel industry more sustainable and profitable.